Many industries employ conveyors for conveying objects between different production stations or between a production station and distribution equipment. Conveyors also occur to a considerable extent within the industry that packs liquid foods in single-use disposable packages. The single-use disposable packages are often manufactured from a packaging laminate containing paperboard with various plastic layers. The single-use disposable packages may, for example, be of parallelepipedic configuration, but they may also be of the gable top type.
The parallelepipedic packages are produced from a continuous web of packaging material. The material web is formed into a tube, in which the product is filled whereafter the material tube is sealed transversely and severed into individual packages. The individual packages are finally formed and thereafter leave the filling machine on a conveyor. The transverse sealing into individual packages often takes place with the aid of a number of transverse sealing jaws which are mounted on a chain.
The industry which packs liquid foods often needs to remove a number of packages from the long row of filled packages departing from the filling machine. For example, it may be desirable to remove one package from each transverse sealing jaw. By taking such samples at uniform intervals, it is possible rapidly to trace possible errors or damage to the filling machine. It is then necessary to be able to remove the packages rapidly and without damaging the removed packages or the packages remaining in place on the conveyor. The intention is also to maintain the packages in the correct number and in the correct sequence. Naturally, there may also be other reasons for removing objects from a conveyor.
Use has previously been made of blow nozzles which have blown off the selected packages from the conveyor in onto one or more lateral supports. But as the filling machines have become increasingly more rapid the demands have also increased on being able to remove a number of packages rapidly and without disturbing the packages which remain on the conveyor.
Modern filling machines may have an output capacity of 15,000 packages per hour. Apparatuses and devices which retard the objects on the conveyor when the selected objects are to be removed can, for such rapid machines, cause a tailback pressure which is so great that the objects, i.e. the packages, which are left on the conveyor are deformed.